Thanks for the info and yes it's a open tort table and my torts will be outside as long as the weather permits. The light is only for the winter months.If you think your tortoise receives enough UV rays from being outside the rest of the year, then you would be ok using this bulb (which does NOT offer the needed UVB) during the winter months. Just know that many people choose not to "risk it" and like a UVA and UVB producing bulb over their indoor tortoises.
You can either buy a 2nd light that offers UVB and use it alongside this bulb, or you can return it to the store for a bulb that emits both.
75watts might not be strong enough to heat up the basking spot. Especially if it's in an open tort table in a cool house. Monitor your temperatures with a reliable thermometer to ensure the temperature is in the 100F range. Only then will you know if 75watts is enough or not.